allow storing config.conf in littlefs and avoid EEPROM use + add RF settings

[eadmaster]

if the SD card is missing store config.conf in littlefs, completely removing use of the EEPROM for settings.
(bruce.conf would be a better name btw)

should be implemented here:
https://github.com/pr3y/Bruce/blob/main/src/core/settings.cpp#L585

Also add a setting for the Rf module in use:

• single-pinned modules (RF433R/RF433T/FS1000A/etc)
• CC1101 (fixed pinout for each board, defined in platformio.ini)

This setting will be used in rf.cpp to init and use the correct module.

Single-pinned modules have a fixed operating frequency, that could be added as another setting and stored in the generated .sub files.

CC1101 receive frequency could also be stored as a setting, or asked interactively via a dialog. (i prefer the former)

Related to: #135

[eadmaster]

if the SD card is missing store config.conf in littlefs, completely removing use of the EEPROM for settings.

@bmorcelli : is it ok if i proceed with this, or are there reasons to keep a copy of the settings in the EEPROM?

[bmorcelli]

with M5Launcher providing the ability to remap partitions, wuth 2 options that doesn't have SPIFFS (partition type o LittleFS), it is intersting to keep things saved on EEPROM.

Have a copy in LittleFS in intersting too, because there are some firmwares that erase this part of the memory (Volos Watch, is an example)

other thing that we must consider, is the existence of such partition, that caused this issue #142

[eadmaster]

2fix: i've reworked the menu here so that it will try to init the cc1101 module to validate the user selection.

However this only works on the 1st try. On the 2nd try the module is reported as connected even if it is not. It may be a bug of ELECHOUSE_cc1101.getCC1101() or something else related to the init function. If you have any ideas pls post here.

[eadmaster]

nevermind, i've just found it was an error in the menu logic, it's fixed now and i can send another pr..